1. Technical Field
This invention relates to a honeycomb structural material, and more particularly to a honeycomb structural material which can be formed of a single sheet of flat material without the need of fastening multiple pieces of material together.
2. Background Art
Honeycomb structural material is used in a variety of applications which range from floor grates, stair treads and sidewalks to grills, louvered panels to load-bearing surfaces for holding other solid panels in spaced relationship, such as structural rigidity for hollow-core doors and sidewalls of cargo containers. They are also used as heat sinks by increasing heat-radiating surface area, or conversely, as in insulation applications, by providing an air barrier between two walls. And finally, they can even be used in a soil stabilization function if they are integrated into the soil surface of an embankment prior to final finish grading of the soil.
The problem is that honeycomb structural material has always been rather difficult to fabricate and bulky to transport because it is usually formed of a plurality of separate pieces which are somehow fastened together to form the honeycomb material at a fabrication plant remote from the final place of use.
Bartels, U.S. Pat. No. 3,752,089 teaches a load-bearing assembly which utilizes a plurality of sub structures scored along longitudinal lines to form individual rectangular sections which are then folded and joined to form a box tube unit. Hutchison, U.S. Pat. No. 3,753,843 teaches a similar structure, except that it takes two sub structures fastened together to form the honeycomb structure. Wennberg et al., U.S. Pat. No. 3,951,730 is yet another development, but it still requires multiple pieces being fastened together to form the honeycomb structural material.
In all of the prior art, multiple pieces are used to form a honeycomb structure. Thus, in all cases, spot welding, lamination, gluing or some other fabrication step is required to form honeycomb structural material, thus making it difficult for on-site assembly.
What is needed then is a method of forming honeycomb material having a plurality of polyhedrons from a single sheet of material without the necessity of fastening sub parts or sub structures together.